Internal pipe coating apparatus



Feb. 26,1963 J. D. CUMMINGS ETAL 3,

INTERNAL PIPE COATING APPARATUS 5 Sheets-Sheet l Filed Jan. .18, 1960Feb. 26, 1963 J. D. CUMMINGS ETAL ,0

INTERNAL PIPE COATING APPARATUS Filed Jan. 18, 1960 5 She Qfc-Sheet 2 INV EN TORI BY 10M24 ATTORNEY Feb. 26, 1963 J. o. CUMMINGS ETAL INTERNALPIPE- COATING APPARATUS 5 Sheets-Sheet 3 Filed Jan. 18. 1960 20 C am011/? ya INVENTORS Feb. 26, 1963 v J. D. CUMMINGS ETAL 3,078,823

INTERNAL PIPE COATING APPARATUS 5 Sheets-Sheet 4 Filed Jan. 18, 1960 4/.H Cum/771x79:

INVENTORJ' BY gQ Z Q llll a; N: 4 .1;

ArroR/vp Feb. 26, 1963 J. D. CUMMINGS ETAL 3,078,323

INTERNAL PIPE COATING APPARATUS 5 Sheets-Sheet 5 Filed Jan. 18. 1960 C.E. Hafcer 4/ AU. Cum/77109:

INVENTORJ BY H ATTOF VV United States Patent, "i re Famed gtlfgii3,078,823 INTERNAL PiPE COATING APPARATUS James D. Cummings, San Marcus,and Craig E. Hatchet, Houston, Tex., assignors toCrutcher-Rolfs-Curnrnmgs, Inc., Houston, Tex., a corporation of TexasFiled Jan. 18, 1960, Ser. No. 3,131 7 Claims. (Cl. 118-306) Oil, gas andother fluid transmission pipe lines may advantageously have theirinterior surface smoothly coated with a corrosion resistant and frictionreducing film and this invention relates to work performing andmechanical handling equipment for quickly and effectively coating theinside surface of hollow objects and particularly pipe sections orjoints which'later are to be connected in end to end and welded togethersuccession in a conduit installation.

An object of the invention is to provide an improved compact and lightweight carriage unit which is self contained and power driven to trackon the inside of a length of pipe and to work the surface thereof duringtravel of the unit from one to the other end of the pipe.

Another object is to provide a carriage storage and transfer device forcooperation in aligned end to end relation with a pipe in enabling thetransfer of a carriage to and from storage position and into and out ofthe pipe.

A further object of the invention is to provide an improved paintoverspray collector baflle ring for co-operation with a pipe end portionand which baffie ring is mounted for rotation slowly during use and iscontinuously wetted with a liquid paint solvent in small amountssufficient to reduce adherence of paint and to flow the solution towardthe bottom of the slowly rotating ring for off-flow into a receivertank.

A still further object is to provide fully automatic plant installationequipment involving a work station at which a pipe to be operated uponis positioned and is engaged at opposite ends by overspray bafilescarried by movable carts, one of which also carries a transfer platformto be longitudinally aligned with a station positioned pipe so that acoating applying carriage can track on and travel from the platform toand through the pipe and back again into inoperative storage position onthe transfer platform whereupon the two end carts spread apart forremoval of the coated pipe in advance of the next succeeding pipe forrepetition of the operating cycle.

Other objects and advantages will become apparent upon reference to theaccompanying drawing wherein FIG. 1 is a small scale elevation ofautomatic equipment for co-operation with opposite ends of a pipe Whoseinternal surface is to be worked and which equipment adjusts itself toany length of pipe within the usual production range; FIG. 2 is a topplan view of a unitary paint applying carriage embodying propulsionmechanism for transferring the paint applying carriage between the pipeinterior and the dolly or cart shown at the left end of FIG. 1 and fordriving the traveling carriage through and back and forth betweenopposite ends of the pipe; FIG. 3 shows the paint applying carriage inside elevation; FIG. 4 is an end elevation as on line 44 of FIG. 3; FIG.5 is an enlarged side elevation of the left-hand cart of FIG. 1 on ascale smaller than that of FIG. 3; FIG. 6 is an end elevation as on line66 of FIG.5; FIG. 7 is a top plan view of the carriage storage platformon line 7-7 of FIG. 5; FIG. 8 is an enlarged side elevation of therighthand cart of FIG. 1; FIG. 9 is an end elevation on line '99 of FIG.8; FIG. 10 is a prespective view of a pipe cleaning carriage; and FIG.11 is a front elevation of a fragment of the pipe cleaning mechanism.

' The arrangement of FIG. 1 will be of special utility for handling pipeat a storage bank of a fabricating mill. Individual joints of pipe 1 areto be rolled forward on the supporting rails 2 to and from a horizontalposition in longitudinal alignment with oppositely disposed trackways 3and 4 and there securely held between a pair of pipe engageable clampjaws 5 which are of a type pivoted at their lower ends in a base plateso that each can be dropped out of the path of the pipe 1. Mounted onand guided by the trackways 3 and 4 for travel toward and from oppositeends of the pipe 1 are motor driven wheeled dollies or mobile carts 6and 7 each carrying a vertically disposed annular ring of substantiallythe same or somewhat larger diameter than the pipe for fitment to thepipe ends as bafi'les therebeyond to paint overspray while the pipe endportions are being coated. Each trackway is of a suitable length toenable cart retraction out of interference to pipe fed to and fromclamped position and to provide a range of cart projection sufficientfor end to end co-operation with different lengths of pipe to beprocessed. Such pipes may vary in length and with respect to ten tothirty-six inch pipe diameters, the lengths usually range betweeneighteen and forty feet. Flexible supply conduits 8 for electricity, airand paint flow as required, run to the carts from retrieving reels 9.

In addition to the overspray collecting bafiie, the cart 6 has atransfer platform assembly 10 to support the mobile carriage forequipment by which work is performed on the interior wall surface of apipe. A mobile paint applying carriage to crawl through the pipe isshown in FIGS. 2, 3 and 4 and includes a main frame or chassis '11having dependent brackets near opposite ends in each of which is mounteda single load supporting wheel 12 which is to track on the lowermostwall portion of the pipe and on the storage platform assembly 10. Themain frame 11 is made up of a pair of transversely spaced andlongitudinally extending steel straps and transversely extending railconnecting members and mounts thereon a pair of drive motors 13 and 14.The rearward drive motor 13 includes as a unit therewith a gearreduction box 15 having a drive sprocket 16 joined by a flexible chain17 to a driven sprocket fixed at one side of the rearmost wheel 12whereby the drive is transmitted to the wheel for propelling thecarriage frame either forwardly or backwardly as controlled by thedirection of rotation of the motor .13. Preferably, but not necessarily,the front wheel 12 may also be employed for traction drive purposes, inwhich event the rearward Wheel carries a drive sprocket for engagementby an endless chain 18 which passes over an idler wheel 19 and isentrained on a sprocket fixed to the side of the forward wheel 12. Thetreads of both wheels preferably are rubber tired for friction driveconformity to the curved interior surface of the pipe wall. The singlefront and rear wheels 12 are preferably disposed in the verticallongitudinal plane of the chassis and an efiort is made to distributethe weight of the chassis and its components so that the load iscentered adjacent the longitudinal central plane. To resist tilting ofthe frame, guide rollers 20 are carried at each side of the frame forengagement with the wall of the pipe at or just below the horizontaldiameter of the pipe. These diametrically oppositely disposed siderollers 20 are mounted for an elastic outward biasing action wherebythey will tend to center the chassis frame within the pipe and willserve to fit pipes of different diameters.

The biased mounting of the idler rollers 20 includes a bell crank leverfor each roller. When four such rollers are employed, as indicated inFIGS. 2, 3 and 4, they are arranged in two sets, one on each side of theframe so that there are a pair of forward rollers and a pair of rearwardrollers, all biased outwardly from the frame and pivotally mountedonvertical axes in the free ends of the bell crank levers 21. The rollercarrying arms of the bell crank levers 21 extend generally in thelongitudinal direction of the frame and those on each side extend inopposite directions from a central journal support. The support includesan outrigger bracket 22 of channel section extending laterally of theframe and terminating in vertically spaced apart horizontal flanges 22aand 2212 through which a pivot pin 23 projects and also projects througha pair of vertically spaced apart forks at the juncture of the two armsof each bell crank 21. From the journal pin 23, bell crank lever armsextend transversely inwardly to a point adjacent the frame center line,with one of the pair of arms terminating in vertically spaced relationto the other arm. As shown in the drawing, the two rear- \vardlyextending bell cranks have their inwardly extending arms terminallyoverlapping one another at a lower level than that of the overlappingends of the inwardly extending arms of the forwardly projecting bellcrank levers. Each end has an elongated slot through which projects astud 24 in the case of the upper arms and a stud 25 in the case of thelower overlapping arm ends. The stud 2-4 also extends through alongitudinally elongated slot or slots in a pair of vertically spacedapart and longitudinally extending straps of a locating frame 26 and hasconnected to the stud 24 one end of a coiled tension spring 27 whoseopposite end is grounded on an anchor pin 28 so that the force of thespring, as seen in FIG. 2, exerts an elastic force on the forwardlyextending bell crank arms to swing both of them outwardly at their freeends which support the side rollers 20. Similarly, the stud 25 extendsthrough longitudinally elongated slots in a lower pair of straps forminga part of the mounting frame 26 and hooked to the stud 25 is one end ofa coiled tension spring 29 whose opposite end is mounted on an anchorpin 30. Accordingly, the roller mounted free ends of the rearward set ofbell crank levers are constantly biased outwardly by the force exertedby the spring 29.

A paint applying unit comprising a hollow spinner head 31 and its drivemotor 14, is mounted in the forward end of the chassis frame and duringdrive of the spinner head a coating paint is supplied through a flexiblehose or conduit 32 leading through the motor chassis to the center ofthe spinner head and is thrown centrifugally outwardly through smallperforations in the periphery of the head. The paint applying spinnerhead 31 having its hub keyed to the shaft of the motor 14 and the motoras a unit, together with the side mounting brackets 22 for the sideroller bell crank rollers as well as the guide frame 26, are mounted ona subframe which itself is carried by the main frame 11 in selectedpositions of vertical adjustment, which enables the spinner axis to bepositioned substantially centrally within any pipe within a range ofdifferent pipe diameters. For purposes of vertical adjustment of thesubframe, the main frame is provided at each side with a pair oflongitudinally spaced apart upright posts 33, each carrying a group ofvertically spaced apart bolt openings 34, into any selected one of whichmay be received a fastening stud 35 which also passes through an openingin an adjacent side rail 36 of the subframe.

Flexible conduits for delivering paint to the spinner and energy foroperating the motors 13 and 14 will extend from the trailing end of thecarriage to a retrieving reel or reels 35 on the transfer cart 6. Thistransfer cart includes a wheeled main frame having a motor and reductiongear drive unit 36 having a chain or belt to one of the supporting andtraction wheels, as seen in FIG. 5. Structural detail of the platformassembly 10 is illustrated in FIGS. and 6 wherein there are seen asextended upwardly from the frame, a series of four screw jack orvertically adjustable corner posts 37 for supporting front and rearmounting plates lying in vertical planes and having concave upper edges,there being fastened to one side of each plate 38 a semicircular strap39 which extends vertically outwardly therefrom and is welded to theouter face of a semicylindrical plate or platform 40. The

platform plate 40 is bent on a radius to conform substantially to thediameter of the pipe with which it is to be used and its boltedconnection to the mounting cradle plate 38 enables interchangeability ofvarious sizes of transfer plates 49. Height adjustment through the screwjacks 37 permits height adjustment of the transfer plate for itslongitudinal alignment with the pipe to be operated upon in order thatthe work performing mobile carriage can be transferred between theplatform 40 and the pipe 1.

On the upper face of the bottom wall surface of the platform 49 thereare prefereably secured as by welding a pair of transversely spacedapart guide ribs 41, as best seen in FIG. 7, and which toward the endnear the pipe are bent outwardly from one another to provide a flaredentrance mouth to the space between the rails 41. These rails serve toguide and center the traction wheels 12 of the mobile carriage as thecarriage passes from the pipe to the storage position on the transferplatform. Contact of the wheels with the flared entrance mouth willserve to center the carriage against any tendency to rock from a properupright position.

Immediately in advance of the forward edge of the transfer platform 40and as best seen in FIG. 5 there is located an annular band 42 of adiameter preferably slightly in excess of the external diameter of thepipe for telescopic fitment to an end portion of the pipe. This bandperipherally carries a pair of circular ribs 43 which track within guiderollers 44 carried within a U-shaped cradling frame 45 projectingupwardly from and being secured to the frame of the cart 6. A pair ofdrive belts 45 are entrained over the upper portion of the rotatableband 42 and are engaged with pulleys on the shaft of a drive motor 46forming a part of the cart 6. During a spray painting operation, thecart 6 is adjusted relative to the pipe end so that the band 42 projectsoutwardly from the pipe end and collects paint which is sprayed beyondthe pipe end. The overspray collector protects the adjoining area fromthe deposit of paint and additionally enables recovery of any paintdeposited on the interior of the ring. For facilitating such recovery,the ring is rotated slowly through the motor 46 and has fed to theinside thereof a suitable paint solvent, as, for example, through adelivery pipe 47 near the bottom of a solvent container 48 supported byone leg of the cradle 45, as seen in FIG. 6. The liquid solvent wets theinterior of the band 42 to prevent the drying of paint thereon and tendsto carry the paint downwardly therewith by gravity to the lower portionof the rotating band 42, from which the excess liquid drops at the sidesinto a collecting tray at the upper end of a storage bucket 49 carriedbelow the ring 42 on the frame of the cart.

Except for the omission of a carriage transfer platform, the cart 7 atthe opposite end of the pipe is much the same as the structure of thecart 6. It involves according to FIGS. 8 and 9, a chassis frame carryinga traction drive motor unit 5t) coupled to one of the supporting wheelsand a drive motor 51 having a pulley for drive belts 52 which runs on acircular collector ring 53. The motor 51, as seen in FIG. 9, has asupport bracket 54 pivoted at one side so that the weight of the motoracts on the belt to eliminate drive slack. Peripheral guide ribs 55 onthe rotatable ring run in grooved rollers 56 carried by a cradle frameassembly 57 projecting upwardly from the cart and a paint solvent supplytank 58 is carried by the cradle with a feed pipe 59 for drippingsolvent on the inside surface of the ring. A solvent collector tank 59is positioned by the frame to underlie the low part of the ring to catchand store the solvent and entrained paint.

In case the inside of the pipe has become dirty or corroded and containsmill scale which needs to be removed in advance of the sprayingoperation, a surface abrading unit can be employed and for that purposethere has been devised the power driven carriage shown eams .5 in FIG.10. This involves a' chassis or mainframe 60 having front and rear driveaxles drive connected with one another through a belt or chain drive 61and carrying pipe engaging wheels 62. One of the shafts additionally isbelted or driven through a chain 63 from a gear reduction box 64 and adrive motor 65 mounted on the frame. The drive motor 65 additionallyacts through a gear box 66 to drive a shaft 67 extending longitudinallyahead of the frame and terminating in a rotatable head 68 on which arecarried a circular succession of air motors 69 whose drive shafts'extendin generally radial directions. Each shaft terminates in a rotary wirebrush '70 for scraping contact with the pipe internal wall. Theindividual brushes rotate about the radially disposed axis andadditionally revolve with the head 68 and co-operate with one another inscraping the internal circular surface of'the pipe. Conveniently, theradial axis of the individual brushes is canted slightly from a trueradial line and for convenience the relative inclination is shown in anexaggerated fashion in FIG. 11. By reason .of the inclination of therotating brush axis, each brush contacts with thepipe onone side of 'itsrotary path and throws'any' scrapings in a longitudinal direction,.thereby not only loosening any dirt but tending also to'b'rushloosedirt ahead of the traveling machine for deposit at the pipe end andclear of the pipe surface.

This cleaning machine may be employed at a station immediately inadvance of the station at which the painting carriage operates, althoughfor some purposes it could operate at the same station and could betransferred to and from a platform similar to the transfer platform 40but carried on the companion cart 7. When separate stations are used,the cart 7 can be eliminated completely at the cleaning station and thecart 6 used for storing the cleaning machine between its action onsucceeding pipe, and of course with the elimination of the paintoverspray ring 42. Alternately, in place of any transfer railed cart,the cleaning machine can be stored on the lift fork of an industrialtruck and by manipulation of the truck can be brought into alignmentwith any pipe to be cleaned.

With the use of the internal pipe coating equipment as described, thesequential operations of the various parts may be manually controlled,as by means of electric switches mounted at a central control panel.Optionally, the sequential operation can be accomplished automaticallyand without manual attention through the use of proper positioned limitswitches. Thus by reference to FIG. 1 and assuming that the jaw clamps 5are ineffective and no pipe is in position, then the advance of a pipeon the rails 2 can be utilized at a given pipe position for actuating aswitch and a closing of the clamp jaws. The response of the clamp jawscan be utilized to actuate switching mechanism for bringing the carts 6and 7 toward one another and into co-operative abutment with theopposite ends of the pipe 1. Such abutment, acting through limitswitches, will stop the cart traction motors and effect rotation of theoverspray rings and also the forward actuation of the traction motor ofthe paint spraying carriage. The carriage will then advance from thetransfer platform and through the pipe to the far end thereof and whenthe travel of the carriage reaches the far end, additional limitswitches are brought into play for reversing the direction of thetraction motor and effecting rotation of the paint spinner motor as wellas feed of paint. The application of the surface coating will continueon the back stroke of the carriage until the carriage is transferredfrom the pipe and onto the storage platform of the cart, whereuponfurther switch actuation will discontinue operation of the carriagetraction motor and spinner motor and paint supply and will directcurrent to the cart traction motors to effect their retraction away fromthe pipe ends to fully retracted position. When such position isreached, switching mechanism will respond for opening the clamp jaws sothat the painted pipe can roll beyond the paint station and the nextsucceeding pipe roll into position to be clamped.

In compliance with the Patent Act, the foregoing specification hasdetailed the structure for fully disclosing the invention but it is tobe understood that various modifications can be made without departingfrom the scope of the appended claims.

What is claimed is:

1. Equipment for coating the interior of pipe, including a pipereceiving station having means to locate the pipe being operated upon, apair of trackways extending outwardly from opposite ends of the pipereceiving station and longitudinally of a pipe located therein, cartsmounted for relative movement on the respective tracks to and from endto end relation with the opposite ends of a pipe located in saidstation, an overspray collecting ring carried by each cart forco-operation with an adjacent pipe end, a carriage transfer platformmounted on pipe to be internally coated, a movable cart arranged fortravel toward and away from the end of a pipe, an upwardly opensemicircular cradle carried by the cart, 21 series of rollers rotatablymounted on the cradle in circularly spaced apart relation and onparallel axes extending in the longitudinal direction of cart movement,an annular ring of substantially the diameter of the pipe and bearing onsaid rollers and projecting upwardly through and above the upwardopening of the cradle, a drive transmitting wheel on the cart and belowsaid cradle, an endless belt entrained on the wheel and on the ring andoperative to hold the ring downwardly on said rollers and to impartrotation to the ring and a cart supporting track extending in thelongitudinal direction of the roller axes and accommodating cartmovement to and from end fitment relation of the ring to the end of thepipe.

3. In an overspray collector for use at the end of a pipe to beinternally coated, a movable cart, a cart support and guideaccommodating cart movement toward and from the end of a pipe to becoated and in the longitudinal direction of the pipe axes, an annularbaflle ring rotatably mounted on the cart for substantially coaxialrelation to the pipe and of substantially the diameter of the pipe formovement with the cart into end to end relation with the pipe as acontinuation thereof and to battle overspray beyond the end of the pipeand drive means on the cart connected to rotate said ring.

4. In a collector as in claim 3 together with a liquid solvent supplytank mounted on the cart and provided with a drip feed pipe positionedto direct a coating liquid solvent on the interior surface of the ringand a collector tray positioned by the cart at the bottom of the path ofring rotation and into which the liquid solvent runs by gravity from thering.

5. Means to fit the end of a pipe while an applicator is directing acoating material on the interior surface of the pipe and to collectcoating material directed radially outwardly beyond said end, comprisingan annular ring for end to end fitment with the pipe and inlongitudinally projecting continuation of the pipe wall beyond the endthereof, a movable cart mounting said ring for travel into and out ofend to end fitment with the pipe and thereby accommodate placement andremoval of pipe in working relation with the applicator and a supportingtrack for the cart extending in the longitudinal direction of the pipeaxis.

6. In a power driven carriage for longitudinal travel within a pipe, acentrifugal spinner head for applying coating on the internal pipesurface, a mounting frame therefor, longitudinally spaced apart wheelssupporting the frame and depending therefrom to ride on the bottom ofthe pipe internal surface, traction drive means connected with saidwheels, two pairs of longitudinally spaced apart guide wheels, one pairof wheels at one side and the other pair at the other side of the frameadjacent a horizontal plane intersecting the pipe axis and to ride onopposite side wall portions of the pipe and mounting means for thewheels comprising two pairs of bell cranks arranged at opposite sides ofthe frame, frame carried pivot connections mounting one pair of crankson a common vertical zutis at one frame side and mounting the other pairof cranks on a common vertical axis at the other frame side with one armof each crank extending longitudinally and oppositely from its pivotconnection in relation to the corresponding longitudinal arm of acompanion crank of the pair and with the other arm of each 7 toresiliently bias the longitudinal arms outwardly from nally beside theframe and the other arrn' transversely projected inwardly, meansmounting said guide wheels on the free ends of the longitudinallyextending arms and spring means interposed between the frame and the[rec ends of the inwardly disposed arms and. active to bias'the hellcranks in directions to urge the guide wheels ontwardly of the frame.

References Cited in the file of this patent UNITED STATES PATENTS1,821,352 McManis Sept. 1, 1931 1,978,853 Albright .d Oct. 31), 19542,351,170 Weinland June 13, 194 2,792,807 Cummings May 21, 19572,800,875 Jewell July 3t, 1957 2,865,321 Von Arx Dec. 23, 1953 2,897,779Perkins Aug. 4-, 1959

1. EQUIPMENT FOR COATING THE INTERIOR OF PIPE, INCLUDING A PIPERECEIVING STATION HAVING MEANS TO LOCATE THE PIPE BEING OPERATED UPON, APAIR OF TRACKWAYS EXTENDING OUTWARDLY FROM OPPOSITE ENDS OF THE PIPERECEIVING STATION AND LONGITUDINALLY OF A PIPE LOCATED THEREIN, CARTSMOUNTED FOR RELATIVE MOVEMENT ON THE RESPECTIVE TRACKS TO AND FROM ENDTO END RELATION WITH THE OPPOSITE ENDS OF A PIPE LOCATED IN SAIDSTATION, AN OVERSPRAY COLLECTING RING CARRIED BY EACH CART FORCO-OPERATION WITH AN ADJACENT PIPE END, A CARRIAGE TRANSFER PLATFORMMOUNTED ON ONE OF THE CARTS, A TRAVELLING CARRIAGE HAVING PROPULSIONMECHANISM THEREON FOR TRACKING ON THE PLATFORM AND WITHIN THE PIPE ANDFOR TRANSFER FROM ONE TO THE OTHER THEREOF AND A SURFACE COATINGAPPLICATOR MOUNTED ON THE CARRIAGE.